01 - WAP to Print Upper Case to Lower Case and vice versa.

This is a Program to print a given letter's from Upper case to lower or Lower case to upper.

#include 
#include 
#include 

int main()
{
 char str[100];
 int idx, option, yes;

 while (1)
 { 
  printf("Select and option:\n1. Lower Case to Upper Case\n2. Upper Case to Lower Case\n");
  printf("Your Option : ");
  scanf("%d", &option);
 
  switch (option)
  {
   case 1:
    printf("Enter a String in Lower Case : ");
    scanf("%s", str);
 
    for (idx=0; idx<=strlen(str); idx++)
    {
      if (str[idx]>=97 && str[idx]<=122)
     {
      str[idx]=str[idx]-32;
     }
    }
    printf("The String in Upper case is : %s\n", str);
    break;
 
   case 2:
    printf("Enter a String in Upper Case : ");
    scanf("%s", str);
     
    for (idx=0; idx<=strlen(str); idx++)
    {
     if (str[idx]>=65 && str[idx]<=97)
     {
      str[idx]=str[idx]+32;
     }
    }
    printf("The String in Lower case is : %s\n", str); 
    break;

   default:
    printf("Invalid Entry!\n"); 
  }   
 
  //this is to run the program
  printf ("\nTo continue press ['Y'/'n'] : ");
  getchar();
  yes = getchar ();
  if (!(  yes == 'y' || yes == 'Y'))  
  break;    
 }
 return 0;
}

Program Output: